EEG and fMRI correlates of behavior during childhood absence seizures [electronic resource].

9781321929720

1 online resource (148 p.)

Access is available to the Yale community.

Childhood absence epilepsy (CAE) is a generalized form of epilepsy causing transitory impairments of consciousness. It is the most common pediatric epilepsy. While absence seizures are often characterized as benign in nature, they have been shown in recent years to cause long-term behavioral and cognitive impairments in children. The syndrome typically begins at 4 to 8 years of age. Seizures are characterized by 3-4 hertz spike and wave discharges on electroencephalogram (EEG) and cause a timecourse of blood oxygenation changes in brain areas seen in functional magnetic resonance imaging (fMRI). However, considerable variability exists in the degree of ictal behavioral impairment from patient to patient and from seizure to seizure. The neural underpinnings of loss of consciousness during absence seizures and the source of behavioral variability are also not well understood. We investigated the underlying neural basis of fluctuations in behavior during seizures through simultaneous behavioral, EEG, and fMRI recordings in pediatric CAE patients during absence seizures. We present evidence to further characterize behavioral impairments during absence seizures using two tasks of continuous performance over time, which require varying levels of attentional vigilance. Task performance was used to categorize seizures as being associated with good or impaired behavior, and performance in epochs of time over the course of seizures was compared. We show that seizures associated with worse performance on task show greater amplitude changes on EEG and show greater changes in overall cortical involvement on fMRI. Seizures associated with poor task performance show greater impairments of well-described cortical networks compared to seizures associated with good task performance. Impaired neocortical function and cognitive deficits significantly reduce the quality of life in patients with CAE. Understanding the fundamental mechanisms of variable behavior in focal epilepsy may lead to improved, targeted therapies for this disorder.

Books / Online / Dissertations & Theses

English

April 12, 2016

Thesis (Ph.D.)--Yale University, 2015.

Yale University.